According to german news reports the name change is because of a large german retail group (Metro) who happen to own several chains of stores that sell consumer electronics.
They only use the name Metro for their wholesale outlets and as a company name though, all consumer focused shops run under different names.
It seems Microsoft has not been ordered to drop the name, but have agreed to do so to avoid any legal problems in the future.
Anyway, that is what the german media has to say about it at the moment.

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